The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1887-10-01
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
MOTION AT REST.

At the ROYAL Institution, London, Mr.. Wins
hurst has exhibited an exceedingly interesting ex-
pertinent in which small type placed on disc re-
yoIving several thousand times q minute was dis
tinctly seen and read while in motion. This was
accomplished by means Of an electrical arrange
ment which caused brilliant sparks to illuminate
the print at the exact instant only when the type
was vertical But for the buzzing produced by
the great velocity of the disc, the words would
have been supposed to be at rest. This applica
fion of the electric spark gives a ready means of
observing any and all changes which may take
place in either matter machinery in rapid motion.
GERMAN LIGHTNING-RIsK.
While danger from lightning appears to have
been increasing in most parts of Germany during
recent years, DIR. Hellmann fLds the reverse to be
the case in Schleswig- Holstein, Baden and Hesse.
Four factors affect the lightning danger to build
ings-the unequal frequency of storms, the geolog-
ical character of the soil, the variability of popu
lation, and the mode of building. Calling the
danger on lime l. that for sand is g. while for loan
it is %. Moisture of the ground adds to the liza
blity of damage, marshy districts being most dan
gerous With like conditions, the relative danger
decreases the more houses are grouped together,
this being conspicuous in Baden, where the light
ming strokes have varied, with locality, from "a to
265 per million houses Buildings with hard roofs
are safest the liability of such houses to be struck
being L. those with soft roofs Z, church towers ~,
and windmills So. In the fifteen years lS69-s3,
there were killed by lightning for every million
men, in Prussia, "A; in Baden, 49, in France,
81 and in Sweden,3
MONSTER TOOL.
One of the finest and most powerful tools that
mechanical science has yet achieved has just been
finished at Mulhouse for the French navy. 1t is
a two-carriage universal lathe which is a complete
machine shop in itself, being capable of perform
ing the most varied operations-such as mortising
shaping, boring and moulding-with the most per-
feet accuracy. 1t is wonderfully adapted to the
delicate and complicated working of pieces for ar
mor-plating turrets, of helix supports OF rudders
of cranked shafts of pstons etc., for modern war
vessels, and it handles and shapes immense masses
of steel almost as skillfuy the carpenter
small blocks of wood. Its weight is more than 34O
tons, and it is driven by an engine of 70 horse
power. Comparison of this tool with one of 70
tons, which was mechanical marvel some %
years ago, gives striking illustration OF the al
most incredible progress of our generation.
AN UNDULAToRY THEORY OF oDoR.
That odor is, like light and sound, phenome-
non of undulation is the belief of NJ. P. Leclerc
He urges that it is reasonable to suppose that
the odors produced by rubbing certain substances
like sulphur and copper-are due to the waves
set up than that the rubbing causes matter to be
emitted which cannot be detected except as smell.
The garlic-odor of heated arsenious acid is smell
accompanying chemical action the same as in
tion with it. With somewhat imperfect apparatus,
M. Leclerc claims to have produced interference
of odors analogous with the interference phenome-
ma of light.
MISCELLANEOUS.
The electric trumpet of NJ. Zigang-which is
adapted to useful service for signaling on ships,
railways, etc.-consists of q short brass tube
mounted on wood and containing an electro-mag-
net whose ends face vibrating plate bearing
small piece of soft iron. A platinum-pointed reg
ulatng screw resting against this plate armature
serves to vary the musical sound which may be
produced with two Leclanche elements.
From records covering more than twenty years,
it appears that the average annual rainfall OF the
whole of India, excluding Burmah and the Lima
Iva, is about AZ inches. The range-one OF tne
most wonderful in the worlds from about 5OO or
600 inches in Cherra Punt to from to inches
in Sindh.
The stems and waste from tobacco are claimed
to be equal to linen for paper, at less than hftn
of the cost.
The color of the sun, if seen from outside the
earth's atmosphere, is believed by Prof. Langley
to be of blush tinge-or, as he describes 1t,
lavender with perhaps suggestion OF purple.
Musical composers are indebted to science for
two new instruments. The melograph-lateiy de-
scribed-is designed to accurately record the notes
of any time played upon piano; and the e.. meio-
trope has Just been devised in France to faithfully
reproduce upon any piano the pieces automatical-
ly copied by the first apparatus.
Specimens of the pearls said to be sometimes
formed in the interior of cocoanuts have been OBJ
tanned in North Ceebes by DR.. Sydney J. Hickson.
He describes them as being about half an inch in
diameter, worn smooth by friction, and consisting
of pure carbonate of lime, with no trace OF vegeta
BILE matter.
Photographs of lightning flashes, which are ex-
pected to be of much Importance in certain re-
searches, are eagerly sought by the Council OF the
Royal Meteorological Society, of London.
An exhibition of useful insects and their pro-
ducts, with noxious insects and specimens of their
injuries, will be open in Paris from August u to
September %. Insecticides and various insect
destroying devices will also be shown.